# Tests common to several calculators
module CalcTestsCommon
  def parser
    @parser ||= @grammar.new_parser
  end

  def test_01_grammar
    assert_kind_of(Rockit::DParser::Grammar, @grammar)
  end

  def test_02_creation_of_parser
    assert_kind_of(Rockit::DParser::Parser, parser)
  end

  def test_03_constant
    ast = parser.parse "1234567890"
    assert_equal("Constant", ast.name)
    assert_kind_of(parser.astclass_of_name(:Constant), ast)
    assert_equal(1, ast.num_children)
    assert_equal("1234567890", ast[0])
    assert_equal("1234567890", ast.num)
  end

  Ops = [["+", :Plus], ["-", :Minus], ["*", :Mul], ["/", :Div]] 

  def test_04_operators
    Ops.each do |op, n|
      num1, num2 = rand(10).to_s, rand(10).to_s
      str = num1 + op + num2
      ast = parser.parse str
      assert_equal(n.to_s, ast.name)
      assert_kind_of(parser.astclass_of_name(n), ast)
      assert_equal(2, ast.num_children)

      assert_kind_of(parser.astclass_of_name(:Constant), ast[0])
      assert_equal(num1, ast[0].num)
      assert_kind_of(parser.astclass_of_name(:Constant), ast.left)
      assert_equal(num1, ast.left.num)

      assert_kind_of(parser.astclass_of_name(:Constant), ast[1])
      assert_equal(num2, ast[1].num)
      assert_kind_of(parser.astclass_of_name(:Constant), ast.right)
      assert_equal(num2, ast.right.num)
    end
  end

  def test_05_paren
    ast = parser.parse "2 * (4 + 67)"
    assert_kind_of(parser.astclass_of_name(:Mul), ast)
    assert_equal(2, ast.num_children)

    assert_kind_of(parser.astclass_of_name(:Constant), ast.left)
    assert_equal("2", ast.left.num)

    assert_kind_of(parser.astclass_of_name(:Plus), ast.right)

    assert_kind_of(parser.astclass_of_name(:Constant), ast.right.left)
    assert_equal("4", ast.right.left.num)

    assert_kind_of(parser.astclass_of_name(:Constant), ast.right.right)
    assert_equal("67", ast.right.right.num)

    assert_equal('Mul[Constant["2"], Plus[Constant["4"], Constant["67"]]]',
		 ast.inspect)
  end

  def assert_calc(expected, str)
    assert_equal(expected, @calculator.eval(parser.parse(str)))
  end

  def test_06_left_associative_operators
    Ops.each do |op, name|
      ast = parser.parse "1 #{op} 2 #{op} 3"
      assert_kind_of(parser.astclass_of_name(name), ast)

      assert_kind_of(parser.astclass_of_name(name), ast.left)
      assert_equal("1", ast.left.left.num)
      assert_equal("2", ast.left.right.num)

      assert_kind_of(parser.astclass_of_name(:Constant), ast.right)
      assert_equal("3", ast.right.num)
    end
  end

  def test_07_mul_higher_precedence_than_plus
    ast = parser.parse "1 + 2 * 3"
    assert_kind_of(parser.astclass_of_name(:Plus), ast)

    assert_kind_of(parser.astclass_of_name(:Constant), ast.left)
    assert_equal("1", ast.left.num)

    assert_kind_of(parser.astclass_of_name(:Mul), ast.right)
    assert_equal("2", ast.right.left.num)
    assert_equal("3", ast.right.right.num)
  end

  def test_08_eval
    assert_calc(2, "2")
    assert_calc(2 * (4+67), "2 * (4 + 67)")
    assert_calc(987 * (456+671), "987*(456+671)")
    assert_calc((9-5) * (100/10), "(9-5) * (100/10)")
  end
end